An enzyme that catalyzes the reduction of a 3 beta-hydroxy-delta(5)-steroid to 3-oxo-delta(4)-steroid in the presence of NAD. It converts pregnenolone to progesterone and dehydroepiandrosterone to androstenedione. EC 1.1.1.145.
Oxidoreductases that are specific for the reduction of NITRATES.
Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
A FLAVOPROTEIN oxidoreductase that occurs both as a soluble enzyme and a membrane-bound enzyme due to ALTERNATIVE SPLICING of a single mRNA. The soluble form is present mainly in ERYTHROCYTES and is involved in the reduction of METHEMOGLOBIN. The membrane-bound form of the enzyme is found primarily in the ENDOPLASMIC RETICULUM and outer mitochondrial membrane, where it participates in the desaturation of FATTY ACIDS; CHOLESTEROL biosynthesis and drug metabolism. A deficiency in the enzyme can result in METHEMOGLOBINEMIA.
A group of enzymes that oxidize diverse nitrogenous substances to yield nitrite. (Enzyme Nomenclature, 1992) EC 1.
Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.
An enzyme that utilizes NADH or NADPH to reduce FLAVINS. It is involved in a number of biological processes that require reduced flavin for their functions such as bacterial bioluminescence. Formerly listed as EC 1.6.8.1 and EC 1.5.1.29.
A FLAVOPROTEIN enzyme that catalyzes the oxidation of THIOREDOXINS to thioredoxin disulfide in the presence of NADP+. It was formerly listed as EC 1.6.4.5
A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC 1.6.2.4.
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
The yellow body derived from the ruptured OVARIAN FOLLICLE after OVULATION. The process of corpus luteum formation, LUTEINIZATION, is regulated by LUTEINIZING HORMONE.
Steroidal compounds related to PROGESTERONE, the major mammalian progestational hormone. Progesterone congeners include important progesterone precursors in the biosynthetic pathways, metabolites, derivatives, and synthetic steroids with progestational activities.
A progestational and glucocorticoid hormone antagonist. Its inhibition of progesterone induces bleeding during the luteal phase and in early pregnancy by releasing endogenous prostaglandins from the endometrium or decidua. As a glucocorticoid receptor antagonist, the drug has been used to treat hypercortisolism in patients with nonpituitary CUSHING SYNDROME.
Compounds that interact with PROGESTERONE RECEPTORS in target tissues to bring about the effects similar to those of PROGESTERONE. Primary actions of progestins, including natural and synthetic steroids, are on the UTERUS and the MAMMARY GLAND in preparation for and in maintenance of PREGNANCY.
The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.
The surgical removal of one or both ovaries.
The period in the MENSTRUAL CYCLE that follows OVULATION, characterized by the development of CORPUS LUTEUM, increase in PROGESTERONE production by the OVARY and secretion by the glandular epithelium of the ENDOMETRIUM. The luteal phase begins with ovulation and ends with the onset of MENSTRUATION.
A flavoprotein amine oxidoreductase that catalyzes the reversible conversion of 5-methyltetrahydrofolate to 5,10-methylenetetrahydrofolate. This enzyme was formerly classified as EC 1.1.1.171.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.
The discharge of an OVUM from a rupturing follicle in the OVARY.
The mucous membrane lining of the uterine cavity that is hormonally responsive during the MENSTRUAL CYCLE and PREGNANCY. The endometrium undergoes cyclic changes that characterize MENSTRUATION. After successful FERTILIZATION, it serves to sustain the developing embryo.
Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 1.6.6.1.
Reductases that catalyze the reaction of peptide-L-methionine -S-oxide + thioredoxin to produce peptide-L-methionine + thioredoxin disulfide + H(2)O.
Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.
A pharmaceutical agent that displays activity as a central nervous system and respiratory stimulant. It is considered a non-competitive GAMMA-AMINOBUTYRIC ACID antagonist. Pentylenetetrazole has been used experimentally to study seizure phenomenon and to identify pharmaceuticals that may control seizure susceptibility.
A pregnane found in the urine of pregnant women and sows. It has anesthetic, hypnotic, and sedative properties.
Drugs used to prevent SEIZURES or reduce their severity.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
Clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. Clinical manifestations include abnormal motor, sensory and psychic phenomena. Recurrent seizures are usually referred to as EPILEPSY or "seizure disorder."
Substances that act in the brain stem or spinal cord to produce tonic or clonic convulsions, often by removing normal inhibitory tone. They were formerly used to stimulate respiration or as antidotes to barbiturate overdose. They are now most commonly used as experimental tools.
Drugs that inhibit 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE. They are commonly used to reduce the production of DIHYDROTESTOSTERONE.
Enzymes that catalyze the transposition of double bond(s) in a steroid molecule. EC 5.3.3.
Catalyze the oxidation of 3-hydroxysteroids to 3-ketosteroids.
Enzymes of the oxidoreductase class that catalyze the dehydrogenation of hydroxysteroids. (From Enzyme Nomenclature, 1992) EC 1.1.-.
A class of enzymes that catalyzes the oxidation of 17-hydroxysteroids to 17-ketosteroids. EC 1.1.-.
Steroid derivatives formed by oxidation of a methyl group on the side chain or a methylene group in the ring skeleton to form a ketone.
Steroids that contain a ketone group at position 17.
A metabolite of PROGESTERONE with a hydroxyl group at the 17-alpha position. It serves as an intermediate in the biosynthesis of HYDROCORTISONE and GONADAL STEROID HORMONES.
Metabolites or derivatives of PROGESTERONE with hydroxyl group substitution at various sites.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
A 21-carbon steroid that is converted from PREGNENOLONE by STEROID 17-ALPHA-HYDROXYLASE. It is an intermediate in the delta-5 pathway of biosynthesis of GONADAL STEROID HORMONES and the adrenal CORTICOSTEROIDS.
A group of inherited disorders of the ADRENAL GLANDS, caused by enzyme defects in the synthesis of cortisol (HYDROCORTISONE) and/or ALDOSTERONE leading to accumulation of precursors for ANDROGENS. Depending on the hormone imbalance, congenital adrenal hyperplasia can be classified as salt-wasting, hypertensive, virilizing, or feminizing. Defects in STEROID 21-HYDROXYLASE; STEROID 11-BETA-HYDROXYLASE; STEROID 17-ALPHA-HYDROXYLASE; 3-beta-hydroxysteroid dehydrogenase (3-HYDROXYSTEROID DEHYDROGENASES); TESTOSTERONE 5-ALPHA-REDUCTASE; or steroidogenic acute regulatory protein; among others, underlie these disorders.
A delta-4 C19 steroid that is produced not only in the TESTIS, but also in the OVARY and the ADRENAL CORTEX. Depending on the tissue type, androstenedione can serve as a precursor to TESTOSTERONE as well as ESTRONE and ESTRADIOL.
A biologically active 20-alpha-reduced metabolite of PROGESTERONE. It is converted from progesterone to 20-alpha-hydroxypregn-4-en-3-one by the 20-ALPHA-HYDROXYSTEROID DEHYDROGENASE in the CORPUS LUTEUM and the PLACENTA.